This invention relates to the protection of beaches, banks and related structures from wind and water erosion.
The interface of land and water presents serious erosion,or land loss problems. In particular, where waves impact land structures, such as beaches or promontories, the wave energy can disturb the land structure causing the land to erode into the water. The damage caused by this action can take years to accrue, such that the day to day or month to month change is imperceptible, or the damage can be seen in a matter of days where high water or unusually fierce storms generate very high waves.
Where the beach or land adjacent a body of water erodes, valuable real estate and improvements may be permanently lost, or the land may be rendered unsuitable for improvements. Ocean and lakefront property, particularly in scenic areas adjacent large cities, is very valuable. Thus, the constant erosion of land adjacent these waters is a costly problem. Further, where the erosion problem is caused by currents, waves or eddies undercutting banks, shorelines or mounting structures, serious damage to the structures adjacent the undercutting can occur. For example, where a jetty or pier is constructed outward into a body of water, currents and eddies can undermine the soil structure at the lake, river or seabed adjacent the footings or pilings which support the structure. The resulting erosion can undermine the integrity of the structure, requiring filling of the eroded area and repair of the structure and footings or pilings.
Many structures have been proposed to address the wave erosion problem. For example, U.S. Pat. No. 315,384, Boynton, discloses a jetty or breakwater constructed of logs attached together in an A-Frame profile in an attempt to dissipate wave energy prior to it reaching the beach or shoreline. Likewise, U.S. Pat. No. 421,631, Sutherland, discloses a breakwater type structure for dissipating wave energy. With regard to beach placed structures, U.S. Pat. No. 2,055,150, Haskett, discloses a water deflector having a screen mounted to one side thereof. And U.S. Pat. No. 4,129,006, Payne, discloses a triangular structure for erosion control. The device includes multiple triangular modules having slits and baffling therebetween.
Applicant herein is a co-inventor of an off-shore breakwater device and an onshore land building device disclosed in U.S. Pat. No. 5,011,328. These devices use a generally triangular profile and cavity to either dissipate and reflect offshore wave energy, or rebuild beach. Applicant is also the inventor of U.S. Pat. No. Re. 32,663, which discloses an interlocking articulated mat of blocks and inserts used for erosion control. The mat may be used to control erosion on banks, beaches, river beds and the like. Each section of mat consists of a central trilobular core piece and three symmetrical blocks. Each block includes three apertures therein for receiving lobes of the trilobular core piece. By placing an aperture of each block on each lobe of the core piece, a amt section emerges. Each section may then be linked with other cores and blocks, to build continuous mat.
The offshore wave deflection and absorption devices are generally expensive to build and install. While that disclosed in my prior patent of which I am a co-inventor, U.S. Pat. No. 5,011,328, may be built modularly, it must be placed offshore below water and thus may require special permits from federal, state or local governments. Further, the permeable breakwater is designed to protect large stretches of beach or shoreline, and is not intended to protect small discrete segments of beach unless special circumstances are present.
The interlocking mat of my prior invention will protect discrete segments of beach, but is more expensive for protection against major wave attack and difficult to place below water to protect pilings and jetties.